From b4564a98fa6ba4c93f3d1fe49909eb170650a888 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Tue, 27 Jan 1998 15:35:30 +0000
Subject: [PATCH] Deadlock ceallnup.
(void) change for aix and hp compilers.
protocol cleanup.
---
src/backend/parser/parse_func.c | 6 ++---
src/backend/postmaster/postmaster.c | 4 ++--
src/backend/storage/lmgr/lock.c | 34 ++++++++++++++++++++++++-----
src/include/access/heapam.h | 6 ++---
src/include/c.h | 14 ++++++++++--
src/include/config.h.in | 2 --
src/include/libpq/pqcomm.h | 10 ++++++---
src/man/lock.l | 8 ++++++-
8 files changed, 62 insertions(+), 22 deletions(-)
diff --git a/src/backend/parser/parse_func.c b/src/backend/parser/parse_func.c
index d864dfc1f6d..52efa3d3960 100644
--- a/src/backend/parser/parse_func.c
+++ b/src/backend/parser/parse_func.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.8 1998/01/20 22:11:55 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/parse_func.c,v 1.9 1998/01/27 15:34:39 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -728,7 +728,7 @@ func_get_detail(char *funcname,
funcname);
elog(NOTICE, "that satisfies the given argument types. you will have to");
elog(NOTICE, "retype your query using explicit typecasts.");
- func_error("func_get_detail", funcname, nargs, oid_array);
+ func_error("", funcname, nargs, oid_array);
}
else
{
@@ -758,7 +758,7 @@ func_get_detail(char *funcname,
elog(ERROR, "no such attribute or function \"%s\"",
funcname);
}
- func_error("func_get_detail", funcname, nargs, oid_array);
+ func_error("", funcname, nargs, oid_array);
}
else
{
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 940047b1e67..8b25be20df9 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.71 1998/01/27 03:11:46 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.72 1998/01/27 15:34:43 momjian Exp $
*
* NOTES
*
@@ -473,7 +473,7 @@ pmdaemonize(void)
int i;
if (fork())
- exit(0);
+ _exit(0);
/* GH: If there's no setsid(), we hopefully don't need silent mode.
* Until there's a better solution.
*/
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index 286824e27f6..a509050704a 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -7,12 +7,12 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.22 1998/01/27 03:00:28 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.23 1998/01/27 15:34:49 momjian Exp $
*
* NOTES
* Outside modules can create a lock table and acquire/release
* locks. A lock table is a shared memory hash table. When
- * a process tries to acquire a lock of a type that conflicts
+ * a process tries to acquire a lock of a type that conflictRs
* with existing locks, it is put to sleep using the routines
* in storage/lmgr/proc.c.
*
@@ -39,6 +39,7 @@
#include "postgres.h"
#include "miscadmin.h"
#include "storage/shmem.h"
+#include "storage/sinvaladt.h"
#include "storage/spin.h"
#include "storage/proc.h"
#include "storage/lock.h"
@@ -1415,7 +1416,8 @@ LockingDisabled()
*
* This code takes a list of locks a process holds, and the lock that
* the process is sleeping on, and tries to find if any of the processes
- * waiting on its locks hold the lock it is waiting for.
+ * waiting on its locks hold the lock it is waiting for. If no deadlock
+ * is found, it goes on to look at all the processes waiting on their locks.
*
* We have already locked the master lock before being called.
*/
@@ -1427,7 +1429,16 @@ DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock, bool skip_check)
XIDLookupEnt *tmp = NULL;
SHMEM_OFFSET end = MAKE_OFFSET(lockQueue);
LOCK *lock;
+ static PROC* checked_procs[MaxBackendId];
+ static int nprocs;
+ if (skip_check)
+ {
+ /* initialize at start of recursion */
+ checked_procs[0] = MyProc;
+ nprocs = 1;
+ }
+
if (SHMQueueEmpty(lockQueue))
return false;
@@ -1457,18 +1468,29 @@ DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock, bool skip_check)
*/
if (lock == findlock && !skip_check)
return true;
- else if (lock != findlock || !skip_check)
+
+ /*
+ * No sense in looking at the wait queue of the lock we are
+ * looking for as it is MyProc's lock entry.
+ * If lock == findlock, and I got here, skip_check must be true.
+ */
+ if (lock != findlock)
{
PROC_QUEUE *waitQueue = &(lock->waitProcs);
PROC *proc;
int i;
+ int j;
proc = (PROC *) MAKE_PTR(waitQueue->links.prev);
for (i = 0; i < waitQueue->size; i++)
{
- /* prevent endless loops */
- if (proc != MyProc && skip_check)
+ for (j = 0; j < nprocs; j++)
+ if (checked_procs[j] == proc)
+ break;
+ if (j >= nprocs)
{
+ checked_procs[nprocs++] = proc;
+ Assert(nprocs <= MaxBackendId);
/* If we found a deadlock, we can stop right now */
if (DeadLockCheck(&(proc->lockQueue), findlock, false))
return true;
diff --git a/src/include/access/heapam.h b/src/include/access/heapam.h
index cb9765c6d5a..3e6e8687805 100644
--- a/src/include/access/heapam.h
+++ b/src/include/access/heapam.h
@@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
- * $Id: heapam.h,v 1.24 1998/01/25 05:04:21 scrappy Exp $
+ * $Id: heapam.h,v 1.25 1998/01/27 15:35:18 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -101,10 +101,10 @@ typedef HeapAccessStatisticsData *HeapAccessStatistics;
#define heap_getattr(tup, b, attnum, tupleDesc, isnull) \
(AssertMacro((tup) != NULL) ? \
((attnum) > (int) (tup)->t_natts) ? \
- (((isnull) ? (*(isnull) = true) : (void)NULL), (Datum)NULL) : \
+ (((isnull) ? (*(isnull) = true) : dummyretNULL), (Datum)NULL) : \
((attnum) > 0) ? \
fastgetattr((tup), (attnum), (tupleDesc), (isnull)) : \
- (((isnull) ? (*(isnull) = false) : (void)NULL), heap_getsysattr((tup), (b), (attnum))) : \
+ (((isnull) ? (*(isnull) = false) : dummyretNULL), heap_getsysattr((tup), (b), (attnum))) : \
(Datum)NULL)
extern HeapAccessStatistics heap_access_stats; /* in stats.c */
diff --git a/src/include/c.h b/src/include/c.h
index 549f3481a68..d031f814e45 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -7,7 +7,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
- * $Id: c.h,v 1.29 1998/01/26 01:41:49 scrappy Exp $
+ * $Id: c.h,v 1.30 1998/01/27 15:35:00 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -181,8 +181,18 @@ typedef char *Pointer;
#endif /* !HAVE_ANSI_CPP */
+#ifndef __GNUC__ /* GNU cc */
+#endif
+
#ifndef __GNUC__ /* GNU cc */
#define inline
+/*
+ * dummyret is used to set return values in macros that use ?: to make
+ * assignments. gcc wants these to be void, other compilers like char
+ */
+#define dummyret char
+#else
+#define dummyret void
#endif
#if defined(NEED_STD_HDRS)
@@ -693,7 +703,7 @@ typedef struct Exception
*/
/* we do this so if the macro is used in an if action, it will work */
#define StrNCpy(dst,src,len) \
- (strncpy((dst),(src),(len)),(len > 0) ? *((dst)+(len)-1)='\0' : (void)NULL,(void)(dst))
+ (strncpy((dst),(src),(len)),(len > 0) ? *((dst)+(len)-1)='\0' : (dummyret)NULL,(void)(dst))
/* Get a bit mask of the bits set in non-int32 aligned addresses */
#define INT_ALIGN_MASK (sizeof(int32) - 1)
diff --git a/src/include/config.h.in b/src/include/config.h.in
index 9c0b1829c1f..521790528f6 100644
--- a/src/include/config.h.in
+++ b/src/include/config.h.in
@@ -216,8 +216,6 @@ extern void srandom(int seed);
* number of seconds.
* We don't check for deadlocks just before sleeping because a deadlock is
* a rare event, and checking is an expensive operation.
- * We only detect deadlocks between two processes, not three or more, but
- * these are the most common.
*/
#define DEADLOCK_CHECK_TIMER 60
diff --git a/src/include/libpq/pqcomm.h b/src/include/libpq/pqcomm.h
index 2a344594331..b3b67f8b73b 100644
--- a/src/include/libpq/pqcomm.h
+++ b/src/include/libpq/pqcomm.h
@@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
- * $Id: pqcomm.h,v 1.20 1998/01/27 04:08:28 momjian Exp $
+ * $Id: pqcomm.h,v 1.21 1998/01/27 15:35:22 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -35,8 +35,12 @@ typedef union SockAddr {
#define UNIXSOCK_PATH(sun,port) \
(sprintf((sun).sun_path, "/tmp/.s.PGSQL.%d", (port)) + \
- sizeof ((sun).sun_len) + sizeof ((sun).sun_family))
-
+ + 1 + sizeof ((sun).sun_family))
+/*
+ * + 1 is for BSD-specific sizeof((sun).sun_len)
+ * We never actually set sun_len, and I can't think of a
+ * platform-safe way of doing it, but the code still works. bjm
+ */
/*
* These manipulate the frontend/backend protocol version number.
diff --git a/src/man/lock.l b/src/man/lock.l
index 8882cf15fb7..0f2060dd5e1 100644
--- a/src/man/lock.l
+++ b/src/man/lock.l
@@ -1,6 +1,6 @@
.\" This is -*-nroff-*-
.\" XXX standard disclaimer belongs here....
-.\" $Header: /cvsroot/pgsql/src/man/Attic/lock.l,v 1.1 1998/01/23 06:01:36 momjian Exp $
+.\" $Header: /cvsroot/pgsql/src/man/Attic/lock.l,v 1.2 1998/01/27 15:35:30 momjian Exp $
.TH FETCH SQL 01/23/93 PostgreSQL PostgreSQL
.SH NAME
lock - exclusive lock a table
@@ -17,6 +17,12 @@ inside a transaction. If you don't exclusive lock the table before the
and do their own \fBupdate\fP, causing a deadlock while you both wait
for the other to release the \fBselect\fP-induced shared lock so you can
get an exclusive lock to do the \fBupdate.\fP
+.PP
+Another example of deadlock is where one user locks one table, and
+another user locks a second table. While both keep their existing
+locks, the first user tries to lock the second user's table, and the
+second user tries to lock the first user's table. Both users deadlock
+waiting for the tables to become available.
.SH EXAMPLES
.nf
--
--
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